U.S. patent number 4,888,706 [Application Number 07/159,690] was granted by the patent office on 1989-12-19 for fluid distribution to multiple users through distributed intelligence sub-centers.
This patent grant is currently assigned to Institute of Gas Technology. Invention is credited to James E. Huebler, William F. Rush.
United States Patent |
4,888,706 |
Rush , et al. |
December 19, 1989 |
Fluid distribution to multiple users through distributed
intelligence sub-centers
Abstract
A process and system for fluid distribution from a principal
intelligence and fluid distribution center to multiple users
through a plurality of distributed intelligence sub-centers. Each
distributed intelligence sub-center has intelligence computing,
analyzing, decision making, and direction capability to provide
control for its portion of the system. The process and apparatus of
this invention provides flow control, leak detection, pipe
condition assessment, user meter readings, pipeline locator
signals, robot control, and pipeline repair and cleaning. The
process provides a total system approach providing improved safety
and reduced operating costs and is particularly suited for
underground distribution of natural gas services.
Inventors: |
Rush; William F. (Tinley Park,
IL), Huebler; James E. (Brookfield, IL) |
Assignee: |
Institute of Gas Technology
(Chicago, IL)
|
Family
ID: |
26856187 |
Appl.
No.: |
07/159,690 |
Filed: |
February 24, 1988 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
395315 |
Jul 6, 1982 |
4729106 |
Mar 1, 1988 |
|
|
Current U.S.
Class: |
700/283; 702/51;
137/624.11; 340/870.05 |
Current CPC
Class: |
G01F
1/00 (20130101); G01F 15/06 (20130101); Y10T
137/86389 (20150401) |
Current International
Class: |
G01F
1/00 (20060101); G01F 15/06 (20060101); G01F
001/00 (); G08C 017/00 (); G08C 019/00 () |
Field of
Search: |
;364/464,465,509,510
;340/870.02,870.03,870.05 ;137/624.11 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Gruber; Felix D.
Attorney, Agent or Firm: Speckman; Thomas W. Pauley; Douglas
H.
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of pending application
Ser. No. 395,315, filed July 6, 1982, to issue as U.S. Pat. No.
4,729,106, on Mar. 1, 1988.
Claims
We claim:
1. A process for fluid distribution through an underground pipeline
system from a single principal intelligence and fluid distribution
center to multiple users, the steps comprising: passing information
obtained from a fluid in sequence from said principal distribution
center through a plurality of distributed intelligence sub-centers,
communicating data between each said distributed intelligence
sub-center and said principal intelligence center and then
communicating said data to an intelligence identifiable user valve
in fluid communication with said underground pipeline system and a
corresponding user meter for each user, communicating said data
between said user valve and said user meter and said distributed
intelligence sub-center, controlling flow of said fluid through
each said user valve upon command from said distributed
intelligence sub-center, providing valve position intelligence to
said distributed intelligence sub-center, providing flow
intelligence of said fluid flow through said user meter to said
distributed intelligence sub-center upon command, controlling a set
of said user meters corresponding to each said distributed
intelligence sub-center by computing and analyzing data to
determine a given output corresponding to a sensed input, and
providing only summary data from said plurality of said distributed
intelligence sub-centers to said principal intelligence center for
general system control by control of fluid and said data to each of
said distributed intelligence sub-centers.
2. The process of claim 1 wherein controlling said distributed
intelligence sub-center includes using a plurality of flow control,
leak detection, pipe condition assessment, user meter reading and
analyzing, pipeline locator signals.
3. The process of claim 2 wherein controlling said distributed
intelligence sub-center additionally includes using robot control
for locating leaks and providing leak locator signals, flow
control, and pipeline cleaning and repair.
4. The process of claim 1 wherein said fluid is gaseous.
5. The process of claim 1 wherein said fluid is liquid.
6. The process of claim 1 wherein communicating said data is
conducted external to a pipeline of the underground pipeline system
by radio waves.
7. The process of claim 1 wherein communicating said data is
conducted external to a pipeline of the underground pipeline system
by wires secured along and exterior to the structure of said
pipeline.
8. The process of claim 1 wherein said user meter provides digital
display upon command.
9. The process of claim 1 wherein each said distributed
intelligence sub-center cumulates fluid flow data from each said
user meter communicating with each said distributed intelligence
sub-center and cumulates flow data from a sub-center meter
providing said flow data of said fluid flow through said sub-center
meter.
10. The process of claim 1 wherein said principal distribution
center cumulates fluid flow data from each said distributed
intelligence sub-center communicating with said distributed
intelligence sub-center and flow data from a principle center meter
providing said flow data of said fluid flow through said principal
center meter.
11. In a process for fluid distribution of a fluid through an
underground pipeline system from a single principal intelligence
and fluid distribution center through a plurality of distributed
intelligence sub-centers to a plurality of individual service
units, the steps comprising: transmitting data from intelligence
identifiable individual service units to one of said distributed
intelligence sub-centers, controlling a set of user meters
corresponding to said one of said distributed intelligence
sub-centers by computing and analyzing data to determine a given
output corresponding to a sensed input providing only summary data
from said distributed intelligence sub-center to said principal
intelligence center in conjunction with said pipeline.
12. The process of claim 11 wherein said fluid is gaseous.
13. The process of claim 11 wherein said fluid is liquid.
14. The process of claim 11 wherein communicating said data is
conducted external to said pipeline by radio waves.
15. The process of claim 11 wherein communicating said data is
conducted external to said pipeline by wires secured along and
exterior to the structure of said pipeline.
16. The process of claim 11 further including providing for
detection of a location of said pipeline from a ground surface by
said distributed intelligence sub-center emitting a locator signal
through said underground pipeline system.
17. The process of claim 11 wherein controlling said distributed
intelligence sub-center includes using a plurality of flow control,
leak detection, pipe condition assessment, user meter reading and
analyzing, pipeline locator signals
18. The process of claim 11 wherein controlling said distributed
intelligence sub-center control additionally includes using robot
control for locating leaks and providing leak locator signals, flow
control, and pipeline cleaning and repair.
19. The process of claim 11 wherein each said distributed
intelligence sub-center cumulates fluid flow intelligence from each
said user meter in communication with it and flow intelligence from
a sub-center meter providing flow intelligence of said fluid flow
therethrough.
20. The process of claim 11 wherein said principal distribution
center cumulates fluid flow data from each said distributed
intelligence sub-center communicating with said distributed
intelligence sub-center and flow data from a principal center meter
providing said flow data of said fluid flow through said principal
center meter.
21. An underground pipeline fluid distribution system to multiple
users comprising:
a principal intelligence and distribution center;
a plurality of distributed intelligence sub-centers, each said
distributed intelligence sub-center controlling a set of user
meters corresponding to each said distributed intelligence
sub-center by computing and analyzing data to, determine a given
output corresponding to a sensed input;
an underground pipeline system in fluid communication through a
supply pipeline with said principal distribution center and said
plurality of distributed intelligence sub-centers and in fluid
communication through distribution pipelines and branching user
pipelines with a user fluid meter serving each said user;
meter computer means at each said user fluid meter capable of
individual identification and activation in data communication with
its corresponding said distributed intelligence sub-center;
sub-center computer means at each said distributed intelligence
sub-center in data communication with and for providing only
summary intelligence to said principal intelligence center.
22. The underground pipeline fluid distribution system of claim 21
wherein said data communication is conducted external to said
pipeline by radio wave means emitting aboveground radio waves.
23. The underground pipeline fluid distribution system of claim 21
wherein said data communication is conducted external to said
pipeline by wires along and exterior to the structure of said
pipeline.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a process and system for fluid
distribution from a principal intelligence and fluid distribution
center, having overall summary control of an entire system, to
multiple users through distributed intelligence sub-centers having
control of a portion of the system. Intelligence transmission from
individual user valves and meters to the distributed intelligence
sub-centers and from the distributed intelligence sub-centers to
the principal intelligence and fluid distribution center is
achieved in conjunction with the piping by means such as wires
within the cavity, wires imbedded in the structure of the piping,
wires along the exterior of the piping, fiber optics, or acoustic,
electromagnetic or optical methods through the piping itself. The
distributed intelligence sub-centers are computers having data
computing, analyzing, decision making, and direction capability to
provide for their area flow control, leak detection, pipe condition
assessment, user meter reading, pipeline locator signals, and robot
control for locating leaks, providing leak locator signals, flow
control, and pipeline repair or cleaning. The process of this
invention provides a total system approach to improved safety and
reduced operating costs for distribution systems and is
particularly well suited for underground distribution of natural
gas services.
2. Description of the Prior Art
Fluid distribution systems, such as natural gas distribution to
residences and businesses, have generally been by underground
piping from a central distribution center through service pipes to
the individual user and through valves and meters at the user end
of the service pipeline. Such systems require reading meters at the
individual user location and are generally not monitored with
respect to fluid theft or leakage. Further, to adjust the flow or
to turn on or to turn off individual user service requires manual
operation at the user location. Generally fluid flow control is
governed by valves at the user service lines and at the central
distribution center, valves in supply lines, if any, frequently
being manual underground valves. Particularly when the fluid is
gas, the user service lines or the supply lines are difficult to
locate, especially by above-ground techniques. Damage to the
service and the supply lines is greatly increased by the present
difficulty in ascertaining their location.
U.S. Pat. No. 4,200,911 teaches control of flow rate and fluid
pressure in a pipeline network by actual fluid consumption
measurement to establish a demand pattern. The predicted demand
pattern for each area is ascertained by comparing characteristics
of each area with those of other areas having standard demand
patterns and the pumps and valves are controlled on the basis of
the predicted demand patterns. This system, however, cannot provide
for unusual demands or emergencies.
U.S. Pat. No. 3,874,222 teaches a leak detection and location
system for a pipeline carrying fluids at different than ambient
temperatures by placement of temperature sensing means to the
exterior of the pipeline. The temperature sensors are located in a
trough to the exterior of a liquid pipeline and provide a signal to
a central monitoring station when other than ambient temperature is
detected. A wide variety of sonic leak detectors have been used for
fluid lines as described in U.S. Pat. Nos. 4,083,229; 3,223,194;
3,055,209; 3,264,864, but none of these systems described in these
patents provide the desired ease and sensitivity of leak detection
for underground gas leaks.
Various methods have been used in the art for pipeline flow
restriction such as exemplified by U.S. Pat. No. 4,291,727 and the
references cited therein. However, the flow restrictor of the U.S.
Pat. No. 4,291,727 requires, in the case of an underground pipe,
that the pipe be exposed and a saddle device attached for interior
access at the point where flow restriction or stoppage is
desired.
The use of pigging devices has been known for cleaning gas
collection lines and various methods have been used for monitoring
the pigs in the pipelines as taught by U.S. Pat. No. 3,384,512.
Various methods for fluid flow control and fluid valve control have
been used based upon pressure sensing as taught in U.S. Pat. No.
3,846,706; electronic measurement of liquid flow utilizing level
and velocity detectors as taught by U.S. Pat. No. 4,202,211;
electromagnetically controlled single water pipe flow with
temperature control by mixing hot and cold for individual demands
as taught by U.S. Pat. No. 2,908,017; control of fluid injection
into the main stream of a system by a flow meter in the main stream
as taught by U.S. Pat. No. 4,007,755; and various specific means of
fluid valve control as taught by U.S. Pat. No. 3,946,287; and fiber
optic control as taught by U.S. Pat. No. 4,306,314.
SUMMARY OF THE INVENTION
This invention relates to a process and system for fluid
distribution from a principal intelligence and fluid distribution
center, having overall summary control of an entire system, to
multiple users through a distributed intelligence sub-center having
control of a portion of the system. The distributed intelligence
sub-center is in both intelligence and fluid communication through
communication means and the pipeline with the user and with the
principal intelligence and fluid distribution center. The
distributed intelligence sub-centers are computers having data
computing, analyzing, decision making, and direction capability to
provide for their portion of the system flow control, leak
detection, pipe condition assessment, user meter reading and data
therefrom, pipeline locator signals, and robot control for locating
leaks and providing leak locator signals, flow control, and
pipeline repair or cleaning. The distributed intelligence
sub-center has the capability of reading all user meters
substantially simultaneously and compare the total of user meter
readings with flow readings of total fluid flow into its portion of
the system to ascertain any difference or unaccounted for fluid. In
addition the nature of such fluid loss may be determined, such as,
in the case where unaccounted for fluid is proportional to fluid
pressure, then leakage is indicated, whereas in the case
unaccounted for fluid is proportional to user demand, then
unmetered use is indicated. Since each distributed intelligence
sub-center may function as an isolated portion of the overall fluid
distribution system and provide full service and control over its
portion of the entire system, problems affecting one distributed
intelligence sub-center portion will not affect a second
distributed intelligence sub-center portion of the system as in
prior fluid distribution systems in which the entire system was
controlled by a single central intelligence and fluid distribution
center.
A user fluid meter is located at each user location and is
intelligence identifiable by and in intelligence communication with
its corresponding distributed intelligence sub-center through
communication means and the piping. Through such communication,
automatic and accurate reading of user meters may be made on demand
from the distributed intelligence sub-center and summarized billing
information or summarized flow information, as desired, may be
transmitted to the principal intelligence and fluid distribution
center. Likewise, the user valve controlling the flow of fluid
therethrough is positioned at each user location and is also
intelligence identifiable by and in intelligence communication with
the distributed intelligence sub-center providing remote turn-on
and turn-off of the individual user service through the piping.
Such intelligence communication allows control and measurement of
fluid flow to the individual user on a continuing basis by the
distributed intelligence sub-center and in a summary manner by the
principal intelligence and fluid distribution center through the
distributed intelligence sub-center.
The distributed intelligence sub-center also is capable of
providing a signal through the intelligence communication system in
conjunction with the pipeline providing for easy above-ground
location of the pipeline. This signal may be used for a detection
system mounted on excavation equipment in order to prevent the
excavation equipment from striking the piping.
An important aspect of this invention is the control of robots
within the piping system by the distributed intelligence
sub-center. The robots may locate leaks and perform leak patching
functions from the interior of the pipeline. The robots may also
provide fluid flow control or stoppage in the pipeline and emit a
signal at the leak site to aid an above-ground repair crew in
pin-pointing the leak site. The robots may also perform cleaning
functions on the interior of the pipe.
The intelligence communication in conjunction with the piping may
be achieved by wires or fiber optics located exterior to, interior
to, or within the piping structure, acoustic means, electromagnetic
or optical means as known to the art.
The distributed intelligence sub-center system of processing
information including computation, analysis, decision making, and
directional control as used in the system of this invention
provides a total system approach utilizing standardized equipment
at each distributed intelligence sub-center, the larger systems
requiring only a larger principal intelligence and fluid
distribution center, as opposed to the requirement of designing the
entire system to accommodate the total size of distribution. The
process of fluid distribution and the system for fluid distribution
to individual users of this invention represents a total system
approach rather than a piecemeal approach to the problems currently
existing in, particularly, underground natural gas distribution
systems. The system of this invention offers flexibility to permit
its use in a variety of existing systems and distribution
requirements.
It is an object of this invention to provide a fluid distribution
system which utilizes identical distributed intelligence sub-center
components to provide computation, analysis, decision making, and
directional control over its portion of the system regardless of
the size of the total system.
It is another object of this invention to provide a gas utility
distribution system providing remote, automatic and accurate
reading of user meters.
It is yet another object of this invention to provide a fluid
distribution system providing individual user remote turn-off and
turn-on of fluid service.
It is still another object of this invention to provide a fluid
distribution system having load leveling capabilities.
It is a further object of this invention to provide a fluid
distribution system wherein maintenance costs are reduced by early
discovery and repair of leaks in pipelines through the use of
robots.
It is yet another object of this invention to provide reduced
incidents of pipeline damage by providing a system in which the
pipeline may be readily located by above-ground techniques.
It is another object of this invention to provide a fluid
distribution system wherein leakage may be promptly detected by a
continuous summation of user fluid use through a distributed
intelligence sub-center and by comparing the summation of multiple
distributed intelligence sub-center use with measurement of fluid
flow from a principal intelligence and fluid distribution
center.
These and other objects and advantages of this invention will
become apparent from the following detailed description of
preferred embodiments and from the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically shows an overall view of one embodiment of the
system of this invention;
FIG. 2 schematically shows the relationship of intelligence between
the user, distributed intelligence sub-center, and principal
intelligence and fluid distribution center;
FIG. 3 schematically shows a portion of distributed intelligence
sub-center and its fluid distribution to individual users;
FIG. 4 shows one embodiment of intelligence communication by
embedding of wires in the pipeline structure;
FIG. 5 shows another embodiment of intelligence distribution by
wires located within the pipeline structure; and
FIG. 6 shows another embodiment of intelligence communication by
wires wound around the exterior of the pipeline structure.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 schematically shows an overall view of one embodiment of the
system of this invention wherein principal intelligence and fluid
distribution center 10 controls the flow of fluid through supply
pipeline 11 to distributed intelligence sub-center 20, shown in
FIG. 1 as 20a, 20b, 20c, 20d and 20e. The principal fluid
distribution center can also be at a separate location removed from
the principal intelligence center. The fluid is passed from the
distributed intelligence sub-center 20 to user 30 through
distribution pipeline 21 connecting with user pipelines 31. In a
preferred embodiment, supply pipeline 11 in addition to providing
fluid transport provides intelligence communication in conjunction
with the pipeline between principal intelligence and fluid
distribution center 10 and the distributed intelligence sub-center
20. It will be readily apparent to one skilled in the art of
communication upon the reading of this description that
communication between all or some of the components of the system
may also be effected by radio waves or any other means external to
the piping and this invention is intended to cover all such means
of communication. As best shown in FIG. 3, distribution pipelines
21 and user pipelines 31 in addition to transporting the fluid,
also provide intelligence identifiable user valve 32 and user meter
34, also referred to as individual service unit, in intelligence
communication through communication wires 35 in user pipeline 31
and communication wires 25 in distribution pipeline 21 to
distributed intelligence sub-center 20. User valve 32 may comprise
a generic valve with an actuator suitable for the particular
service and user valve 32 can be connected to user pipeline 31 by
any suitable method known to the art, such as a screwed connection,
a welded connection, a flanged connection or the like. Each user
valve 32 controls flow of fluid therethrough upon command from the
distributed intelligence sub-center 20 and also communicates to
distributed intelligence sub-center 20 the position of user valve
32 at all times. Each user valve 32 communicates with distributed
intelligence sub-center 20 by the user valve 32 having a
microprocessor which is connected to a standard interface via a
communication link, such as a telephone modem, radio signals or
other suitable communication link means known to the art.
The distributed intelligence sub-centers are computers having data
computing, analyzing, decision making, and direction capability to
provide for their portion of the system flow control, leak
detection, pipe condition assessment, user meter reading and data
therefrom, pipeline locator signals, and robot control for locating
leaks and providing leak locator signals, flow control, and
pipeline repair or cleaning. Suitable computers for performing
desired functions of the distributed intelligence sub-center are
known to the art, such as, a single board computer having the
characteristics: Power: +5 VDC, +12 VDC; Ports: 2 asynchronous
serial ports (one with control lines-modem), bus expansion slot or
port for general Input/Output, parallel port; Memory: 6416
allowable operating system size (ROM), 1 Meg accessible (RAM)
memory. An OPTO-MUX, Model LC200 computer is an example of a
suitable computer for use as a distributed intelligence sub-center.
Exemplary of the distributed intelligence sub-center computer
functions are the following:
Automatic (time variant) Individual Polling
On Command Individual Polling
Relay commands from higher level down
Transmit HDLC formatted message
Calculate Frame Check Sequence (FCS) Error Checking
Receive HDLC formatted messages
Decode received Individual Service Unit messages
Decode received District Messages
Decode received principal intelligence and distribution center
messages
Store the following Individual Service Unit information:
Total Meter Reading
Base Meter Reading
High Rate Meter Reading
Low Rate Meter Reading
High Billing Rate
Low Billing Rate
Meter or Unit Configuration
Meter Throughput
Current Flow
Ongoing Flow History
Individual Service Unit Status
Valve Status
Service Pressure
Service Temperature
Service Cathodic Protection Reading
If meter, Outstanding bill
Check status of Individual Service Unit
Display and print alarm log
Acknowledge and Clear Individual Service Unit Alarms
"Roll Over" Time dependent meter reading data base Tabulate Hourly,
Daily, & Weekly Meter totals
Decode and Act on the following HDLC protocol controls:
Receive Ready
Receive Not Ready
Reject frame sent
Poll command
Information frame
Invalid Command
Data Base Key search
Individual Service Unit initialization and/or
reparameterization
Service and act on following HDLC controls:
Selective Reject
Disconnect Mode command
Request Disconnect Mode
Set Initialization Mode
Request Initialization Mode
Exchange identification
Reset counters
Test communication link
Frame Reject
Set Normal Response Mode
Set Extended Normal Response Mode
Test Valve
Open and close valve
Emergency Status action procedures
Change Hi - Lo Billing rates
Mark New Billing Period
Mark Start & Stop Meter Throughput History
Excess Flow Set Point
Gas Flow Calculation
Each distributed intelligence sub-center 20 controlling fluid
distribution to multiple users 30 may control the rate of fluid
flow or may shut off or start up the flow of fluid to any
individual user through user valves 32. Likewise, user meter 34,
upon being addressed by intelligence communication from the
distributed intelligence sub-center reports via the intelligence
communication through the pipeline to the distributed intelligence
sub-center the fluid flow rate or the accumulated volumetric fluid
flow over a period of time through user meter 34. Each distributed
intelligence sub-center 20 has microcomputer 22 in communication
through communication wires 25 and 35 with each user valve and user
meter and sub-center distribution meter 13 and through
communication wires 15 with a main computer in principal
intelligence and distribution center 10.
One of the important aspects of the fluid distribution systems of
this invention is illustrated in FIG. 2 showing intelligence flow
between individual user valves and user meters, individual service
unit, and a corresponding distributed intelligence sub-center
(DISC). Each distributed intelligence sub-center may monitor fluid
flow for leakage throughout the user population it services. Each
distributed intelligence sub-center, 20a, 20b, 20c and 20d, obtains
meter readings from the user meters within its territory and
performs all data computing, analyzing, decision making, and
direction functions such as a programmed output signal response to
a given input signal detected by, for example, an unacknowledged
alarm, an out of range sensor, or the like; each distributed
intelligence sub-center 20a, 20b, 20c and 20d supplies for its
territory only necessary summary data for billing or overall fluid
distribution to the principal intelligence center 10 (PIC). Thus,
the distributed intelligence sub-centers may be standardized for
providing service to a number of users and the overall system size
adjusted by the number of distributed intelligence sub-centers and
only the capability of the principal intelligence center need be
adjusted for the size of the overall system. The distributed
intelligence sub-center provides a network of similar
microprocessors with data computing, analyzing, decision making,
and direction capability for its territory distributed throughout
the system and monitored by a modest central computer for handling
only summary information in the principal intelligence center.
User meters 34 may be located at any position in user pipeline 31,
either within or near the user structure or close to distribution
pipeline 21, both as shown in FIG. 3. Location of the user meters
near the distribution pipelines would reduce vandalism and user
theft. User meters suitable for use in the system of this invention
may operate on any principle measuring fluid flow, such as positive
displacement, rotary displacement, turbine or acoustic means of
measurement. The user meters for use in the system of this
invention are characterized by translating the meter reading into a
data form for transmission to the distributed intelligence
sub-center upon being addressed by a signal from the distributed
intelligence sub-center.
In a preferred embodiment positive displacement meters with
mechanical indicating arms are employed with the addition of an
individual service unit, such as integrated circuit chips to
digitally encode the meter reading into an electronic signal and to
render each meter individually addressable. The integrated circuit
chips may be activated to encode the meter reading and to transmit
the reading to the corresponding distributed intelligence
sub-center through the intelligence communication system of the
piping. This is accomplished by use of an addressable two-way
asynchronous communication chip as exemplified by CMOS circuit type
MC14469T or similar devices as will be familiar to those skilled in
the art. Each individual service unit is hard wired to have its own
address and is enclosed within the service line until it reaches
the main at which point it passes through the wall of the service
line and is connected to the conductor cable. When the individual
service unit receives a set of electronic pulses from a distributed
intelligence sub-center, it first compares its address with the
address pulse code that it has received. For the particular circuit
indicated above, the last bit in the word indicates whether the
word is an address or a data string, but it will be obvious to one
skilled in the art how other specific circuits of a similar nature
can be applied to achieve the same end. The particular circuit
described above is capable of application to distributed
intelligence sub-centers servicing 12 individual service units.
Upon being activated, the individual service unit chip will
activate the meter reading, switch on the indicator that indicates
the rate in effect for the gas, terminate service, recharge the
batteries in the meter, activate and interrogate an in-place leak
detection system composed of microphones or other sensors in or
attached to the main, or read either a water or electric meter if
so desired by the utility. The circuit indicated above has
considerable additional capability to perform other functions. In
the described preferred embodiment, the meter reading may be
performed by either reading of the mechanical positions of the
meter hands by the same methods that are currently employed to
remotely read meters or by optically chopping a light beam which is
incident on a series of holes that are drilled in one of the gears
in the mechanical gear train in the meter mechanism. This optical
encoding, or alteratively, pulse counting can be accomplished by
employing a light emitting diode and a light sensitive detector in
a manner that will be familiar to one skilled in the art. The meter
may be equipped with a pair of indicator lights that can be
activated by a customer pressing a button on the meter display. The
indicator will show whether the normal or an increased or reduced
rate is in effect at that particular time for the gas purchased.
These indicators are driven by and Q and Q outputs from any of the
standard flip-flop circuits that are familiar to one skilled in the
art. These flip-flop circuits are driven to change state by one of
the output leads from the individual service unit circuit. Service
termination is also the result of a signal originating within the
individual service unit in response to an appropriate distributed
intelligence sub-center code instruction. The signal drives an
electrically activated valve mechanism of any standard design.
Service cannot be restored unless a special key is used to reopen
the valve mechanism and the state of the flip-flop is changed by an
electrical command. The mechanism is prevented from running down
associated batteries by a microswitch which is in series with the
device and opens when the valve closes. The rechargeable batteries
that are enclosed in the meter case protect the meter and its data
from power failure. The system described above will be seen to fail
in its position at the time of failure. Thus, a power failure
neither terminates nor restores services and the batteries prevent
loss of data during the failure. The batteries are recharged by
using a transistor to switch the battery across the power and
ground leads to allow it to be recharged. Alternatively, the
battery can be charged from a flow powered device enclosed within
the meter.
Since the reading is provided by a mechanical mechanism, meter
information is not lost in the event of a power failure. The user
meter for use in the system of this invention is compatible with
the mechanical and the data carrying requirements of the system.
Energy for the functioning of the user meter may be supplied
through the pipeline intelligence communication system or may be
derived through flow energy extracted from the fluid flow in the
system, or through external power lines. Such energy may be stored
either mechanically or as electrical energy. Remote user meter
reading capability benefits both the utility and the customer by
reducing the operating cost of the distribution system. Further,
the remote reading capability permits short term readings, such as
on an hourly or multiple hourly basis to permit variable rate
pricing to encourage off-peak consumption. Present systems use two
meters to provide only two different rates. The user may also be
provided with information of fluid consumption provided by user
meter display 33, shown in FIG. 3. The user would cause the
integrated circuit chip to present the user meter reading on an LED
or LCD display. The user meter chip could also provide an output
signal directed to the user's computer to afford the user a
computer controlled energy management system, in the case of the
supply of natural gas. More accurate metering of gas is possible by
the user meter integrated circuit chips having a temperature sensor
compensating the flow measurements for pressure and temperature
variations.
Associated with user meter 34 is user valve 32. The same integrated
circuit chip monitoring the user meter may also monitor and control
the user valve. User valves suitable for use in the system of this
invention are mechanical valves which remain in a set position
unless provided an electrical signal for changing the valve
position. Thus, in the event of an electrical failure, the user
valves remain in the position in which they are at the time of
failure. The user valve has a sensor which can inform the
distributed intelligence sub-center of the valve positioning
through the intelligence communication through the piping.
Likewise, each user valve is intelligence identifiable and thus may
be addressed by the distributed intelligence sub-center and
actuated for a valve position change. One important capability of
the system of this invention is enhanced user safety by providing
for high speed distributed intelligence sub-center shutting down of
gas service to a user's home in case of fire or emergency, or to a
number of users simultaneously if there were a natural or
accidental catastrophe in which user valves could not normally be
reached from a principal or central control center. Also, service
to an individual user may be readily turned off and turned on by a
distributed intelligence sub-center in cases of intermittent
occupancy, such as summer homes or ski lodges. Further partial
service shut down can be achieved in cases where it is desired to
only supply gas sufficient for a selected number of user
appliances, such as to provide sufficient gas to prevent users who
do not pay for the service from suffering serious harm because of
loss of gas service.
The distributed intelligence sub-center also controls valves in
distribution pipelines 21 to control fluid flow to geographical
areas of multiple users under each sub-center control. The
distribution pipeline valves desirably permit passage of robots
through the distribution pipelines as will be more fully described
herein. The distributed intelligence sub-center in communication
consultation with the principal intelligence center may control and
measure fluid flow from supply pipeline 11 to distribution
pipelines 21 through supply valve 12 and sub-center supply meter
13.
All of the valves are standard design mechanical valves, such as
gate or ball valves. The valve status, open or closed, may be
indicated by a pair of light emitting diode and light sensitive
detectors on opposite sides of the valve closing element. Power to
operate the valves may be derived from internal batteries,
electrical lines or from flow energy derived from passage of fluid
through the system. The valves may be remotely addressed and
operated using the same electronics as described above for the
individual service units.
In cases of all of the valves, intelligence transmission must occur
through or around valves regardless of the valve position. In the
embodiments utilizing fibers or wires for intelligence transmission
through the pipeline, this is readily accomplished by embedding the
fibers or wires in the housing of the valve wall or by carrying the
information through lines that are outside of the housing. In the
embodiments using the interior of the pipe itself as a data
conductor, such as acoustic systems, microwave and the like, the
valve may use a repeater unit on each side of the valve to repeat
the signal or the valve closing element may be fabricated from a
material transparent to the data signal, such as plastics which are
transparent to microwaves, making such repeaters unnecessary.
Intelligence communication between the user meters and user valves
and the distributed intelligence sub-center may be achieved by any
suitable means. External communication means, such as radio waves
may be used. Internal communication means through the piping itself
has several advantages. The pipe may have intelligence carrying
lines embedded within its walls, as shown by wires 25 in FIG. 4,
which may involve fiber optics or electrical transmission. The
intelligence transmission lines, such as 25, may be in the interior
of pipeline 21 as shown in FIG. 5, or to the exterior of pipeline
21 as shown in FIG. 6. When continuous intelligence transmission
systems, such as fiber optics or electric wires, are used, the pipe
connections and pipe fittings are constructed to accommodate
connection of the intelligence transmission lines. When different
modes of intelligence transmission are used in the same system,
they must be interfaced between the portion of the system having
one mode of data intelligence transmission and a second portion of
the system having another mode of intelligence transmission, such
as electrical conductors to fiber optics.
In case of electrical wires carrying intelligence throughout the
pipeline, multiple parallel wires may be connected at intervals to
provide a high degree of redundancy to the system in case of
breakage of a wire. Embedding the electrical wire in plastic piping
and in the plastic pipe fittings, protects the electrical
conductors from corrosion. Optical fibers in the pipeline itself
provide the advantages of sensitive acoustic, stress, and heat
detection. Acoustic means of communication through the pipeline
provide easiest retrofitting to existing systems.
In a preferred embodiment plastic pipe is formed and installed in
the conventional manner. However, just prior to installation, two
sets of four wires are installed below the pipes in separate
cables. These wires are connected at intervals of approximately 30
meters to provide redundancy in the event of a break in one of the
leads. The cables are separated from one another by approximately
half of the pipe diameter. Two of the sets of wire are a small
gauge (20) and the other two are of heavy gauge (12). For
installation in existing systems that are being renewed by
insertion, the cables of wires are inserted into the old pipe at
the same time the new mains are inserted. When the customer's
service is installed or renewed, an electrical connection is made
to the main cable to connect the customer's meter to the
distributed intelligence sub-center. The electrical leads enter the
service line near the main and enter the customer's premises
encased in the line to prevent tampering with the system.
Protection against electrical power failure is provided by
generating the required electricity at each distributed
intelligence sub-center with a gas turbine generator. This unit
operates at 400 hertz to distinguish its signals from the 60 hertz
of the electrical grid. The heavy gauge wires are called the power
lead and the ground lead and the other two leads are called the
transmit and receive leads. The receive lead carries data from the
meter to the distributed intelligence sub-center and the transmit
lead carries data from the distributed intelligence sub-center. The
ground line is common to all circuits. The power lead is used to
carry the buried pipe location signal which is generated at the
distributed intelligence sub-center. In addition, the pipe is
compatible with robot operation. The minimum pipe opening is large
enough to permit the passage of robots which is at least 5
centimeters for mains. The radius of curvature of bends is large
enough to permit robots to negotiate turns and therefore at least 8
pipe diameters. There are no obstructions into the pipe interior to
interfere with robot passage and tees and crosses are large enough
to permit robot turns. Installation of the pipe is done so as to
avoid sharper inclines than robots can negotiate, and are thus not
steeper than 30.degree.. At each distributed intelligence
sub-center there is also a robot port that is accessible from the
surface to permit access to robots for periodic maintenance and
replacement with special purpose and improved robots. At these
robot ports, the robots can recharge their batteries and park out
of the main flow path of the fluid.
In one preferred embodiment, leak detection may be built into the
system by providing stationary acoustic sensors along the pipeline
as part of the communication system.
In one preferred embodiment of this invention the piping has
conductors capable of carrying a locator signal as part of the
intelligence communication system, the locator signal being readily
detectable by ground surface detection equipment. The detector
signal can be continuously applied or intermittently applied as
desired. With all of the underground piping carrying a locator
signal, there should be a great reduction in damage to such piping.
The damage may be even further reduced by providing an alarm on all
digging equipment used in the vicinity of such pipelines, the alarm
being adjusted to sound when the digging equipment is within a
pre-selected distance from the pipeline.
Distributed intelligence sub-centers according to this invention
are small computers having data computing, analyzing, decision
making by implementing programmed decisions, and direction
capability to receive data and process it to control all
distribution associated activities in its territory and to process
and transmit only summary results to a principal intelligence
center. The distributed intelligence sub-center is capable of
receiving intelligence from and transmitting intelligence to user
meters, user valves, distribution pipeline valves, pipeline
sensors, or robots within the territory covered by the distributed
intelligence sub-center and transmitting locator signals. The
locator signals may be detected by above ground detector 40. The
distributed intelligence sub-center has means for addressing the
individual meters, valves and robots, and means for identifying
user meters, valves or robots which have transmitted intelligence
to it. The distributed intelligence sub-center contains emergency
procedure instructions, routines for sequential user meter readings
and routines for computing and comparing actual and expected gas
consumption. The distributed intelligence sub-center may process
and transmit summary information from the user meters or valves or
robots to the principal intelligence center through the supply
pipelines. The microprocessor used in the distributed intelligence
sub-centers may be of any suitable configuration which will perform
the reading and calculation functions described above and will be
appropriately interfaced with the lines that carry data to the rest
of the system. In a preferred embodiment, the microprocessor is a
NSC 800 microprocessor chip or its equivalent. The connection to
the rest of the system is accomplished through use of any of the
Universal Asynchronous Receiver/Transmitter chips which will be
familiar to those skilled in the art. The distributed intelligence
sub-center microprocessor is similarly connected to the principal
intelligence center for provision of summary and processed
information.
As shown schematically in FIG. 3, distributed intelligence
sub-center 20 is physically an underground vault rendering a robot
port 27 physically available for maintenance or replacement and has
intelligence repeater 23 above ground for easy information
access.
In a preferred embodiment of this invention, one or more robots may
be used in connection with each distributed intelligence
sub-center. As shown in FIG. 3, robot 28 is operated in
distribution pipeline 21 from distributed intelligence sub-center
20. Robots 28, capable of performing robotic functions to inspect
pipelines as described in this specification, are commercially
available and usually comprise a battery powered mobile platform
capable of moving within a pipeline. If a pipeline as shown in FIG.
5 is used, intelligence transmission lines 25, such as fiber optics
or electric wires, should be secured to the inside wall of pipeline
21 by suitable means known to the art, such as epoxy or the like.
The dead end of distribution pipeline 21 within the distributed
intelligence sub-center vault provides robot port 27 and robot
storage section 26 readily accessible from the sub-center vault.
Each robot is controlled by and provides information to its
corresponding distributed intelligence sub-center. The robots may
be battery powered and operate at low voltage within the pipeline,
eliminating the danger of spark and the need for the robot to drag
a wire which can become heavy and tangled. The robots may also
derive energy from the system through tracks, power lines or flow
energy of the fluid. The robots may be designed to perform a number
of functions such as leak detection, determination of pipe
condition, repair of leaks from the interior of the pipe, and may
transmit a "homing" signal to aid repair crews above ground in
pinpointing the robot position in the pipe, such as for repair of a
leak. The robot may also carry emergency flow stoppage equipment
and may thus shut off fluid flow in a section of the system.
The robots may readily locate very small gas leaks by traveling
through the pipe and using sonic leak detection equipment which is
very sensitive due to its proximity to the leak. The robots may
also provide visual or computer controlled image inspection of the
pipe condition.
The primary requirements for robots for use in this invention are
mechanical compatibility with the rest of the system hardware and
the ability to communicate with the distributed intelligence
sub-center even under conditions of system emergency, including
major natural disaster. Because a variety of robots will be
required for specialized tasks, only the general characteristics of
robots will be described along with a few specific examples of
robot configuration. Robots may have any configuration, but in
general, they must provide minimal impediment to flow. In a
preferred embodiment, robots are powered by rechargeable batteries
and driven by electrical motors. Motors are of the explosion-proof
design to eliminate dangers of robot operation in situations of
possible air leaks into the system. In general, robots are long,
thin carts which are driven by two motor driven rear wheels. In the
preferred embodiment, the robot is steered by a single front wheel.
The steering wheel may be turned to the left or right and the
wheels may be driven forward or backward at a proportionally
controlled rate. The mechanism for constructing such a vehicle and
controlling it remotely through radio waves is well known to those
skilled in the art and is similar to the units that are available
for remote controlled cars, boats and model airplanes. The robots
contain a microprocessor similar to that used in the distributed
intelligence sub-center and are programmed with a variety of
routines for navigation and operation as well as communication. In
a preferred embodiment, robots are equipped with sensors that
detect light (front, rear and side) by means of light sensitive
detectors, sound by a microphone of any standard design, water by
means of a pair of wires that will conduct a current if water is
present in the pipe and obstacles by means of spring loaded bumpers
connected to electrical contacts that are closed if either the
front or rear bumper encounters an obstacle. Robots also have a
switch which closes if the robot turns upside down. In the event
that the robot encounters certain emergency conditions inside the
pipe, such as water, unexpected light, obstacles, or robot
turnover, the robot microprocessor is programmed to inform the
distributed intelligence sub-center of the sensor reading
indicating an emergency condition. In a preferred embodiment, types
LM1871 and LM1872 chips are used for transmission. Microphone sound
readings are encoded and transmitted to the distributed
intelligence sub-center for analysis in search for possible leak
conditions. As a specific example of the types of robots that are
used in a preferred embodiment, leak patrol robots and rescue
robots will be described. Leak patrol robots are equipped with the
normal complement of sensors described above and in addition to the
normal low quality microphone, a high quality microphone is
provided for detailed analysis of the sonic spectrum of the leak.
The signal level can be transmitted to the distributed intelligence
sub-center which will both assist the robot in locating the highest
signal level location, thus pinpointing the leak, and compare the
signal level with the levels expected for the flow conditions
current in that part of the system. In addition, the signal can be
transmitted directly for spectral analysis and interpretation of
leak size ad shape. The leak patrol robot can either transmit a
homing signal by activating an acoustic transducer which will guide
leak repair crews to the location or else release a charge of
compressed carbon dioxide to inflate a balloon type device to shut
off the flow of gas to the leak area. Rescue robots are
specifically designed to retrieve robots that become stranded
because of turning over or running out of power. These robots are
equipped with more powerful driving mechanisms and higher traction
wheels than are standard robots in order to drag heavier loads.
Stranded robots are connected to the rescue robots by a hook that
latches over their bumpers.
Robot navigation is aided by several techniques. Distances are
approximated by counting the revolutions of the non-driven wheel
using an up-down counter that counts the wheel rotations.
Navigational checkpoints are provided by flashing lights placed
inside the pipe at critical locations. For example, when a robot
approaches a particular valve, the distributed intelligence
sub-center can instruct the valve computer chip to flash its
condition indicating light emitting diode at a particular
frequency. A map of the system with the distances, locations and
frequency of each flashing light is programmed into the memory of
the robot and the distributed intelligence sub-center. The light
sensors on the robot can report the presence of a flashing light
and its frequency and then using said map of the system when the
light detector on the side of the robot detects the light, the
distance counter can be corrected or rest to zero by the robot's
microprocessor. Thus, precise location of the robot is recalibrated
periodically and relayed to the distributed intelligence
sub-center.
It will be apparent to one skilled in the art that there are many
possible variations to the details, including method of information
example, that many other integrated circuit components are
currently available that could be used, or that will become
available in the future, or that could be specifically designed and
manufactured for the purposes described. The wide range of computer
hardware available for the user valves and meters, robots,
distributed intelligence sub-center and for the principal
intelligence center has not been described in detail since it would
be readily apparent to one skilled in the art upon reading this
description. Likewise, particular mechanical valves, meters, robots
and means of communication suitable will be readily apparent after
reading the description of this invention. It is also apparent that
the fluid distribution system of this invention, once installed,
permits great flexibility in its use and its easy adaptation to
advances in technology.
The installed intelligence communication system used in the fluid
distribution system of this invention may be utilized for
additional services. For example, the fluid distribution system of
this invention used for gas distribution may be readily utilized
for remote reading of water and electric meters by passing the
meter electronic data output through the intelligence communication
of the gas distribution system. Additional addressable individual
service unit circuitry is not required to provide these additional
functions since each is simply an additional function of the
already in place individual service unit.
While in the foregoing specification this invention has been
described in relation to certain preferred embodiments thereof, and
many details have been set forth for purpose of illustration, it
will be apparent to those skilled in the art that the invention is
susceptible to additional embodiments and that certain of the
details described herein can be varied considerably without
departing from the basic principles of the invention.
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